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<div><a href="../../index.html">Home</a> &gt;  <a href="../index.html">CO4OI</a> &gt; <a href="index.html">misc</a> &gt; fast_tensor_product.m</div>

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<h1>fast_tensor_product
</h1>

<h2><a name="_name"></a>PURPOSE <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="box"><strong></strong></div>

<h2><a name="_synopsis"></a>SYNOPSIS <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="box"><strong>function [ X ] = fast_tensor_product( x ) </strong></div>

<h2><a name="_description"></a>DESCRIPTION <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="fragment"><pre class="comment">
   fast_tensor_product - computes the tensor product of vector x with
   itself

   OUTPUT: X = x \otimes x \otimes x</pre></div>

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<h2><a name="_cross"></a>CROSS-REFERENCE INFORMATION <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
This function calls:
<ul style="list-style-image:url(../../matlabicon.gif)">
</ul>
This function is called by:
<ul style="list-style-image:url(../../matlabicon.gif)">
</ul>
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<h2><a name="_source"></a>SOURCE CODE <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="fragment"><pre>0001 <a name="_sub0" href="#_subfunctions" class="code">function [ X ] = fast_tensor_product( x )</a>
0002 <span class="comment">%</span>
0003 <span class="comment">%   fast_tensor_product - computes the tensor product of vector x with</span>
0004 <span class="comment">%   itself</span>
0005 <span class="comment">%</span>
0006 <span class="comment">%   OUTPUT: X = x \otimes x \otimes x</span>
0007 
0008 N=size(x,1);
0009 x1=x.'; x1=x1(ones(1,N),:,ones(1,N)); <span class="comment">%equivalent to x1=repmat(x.',[N,1,N]);</span>
0010 
0011 x2=x(:,ones(1,N), ones(1,N)); <span class="comment">%equivalent x2=repmat(x,[1,N,N]);</span>
0012 
0013 x3=zeros(1,1,N);
0014 x3(1,1,:)=x;
0015 
0016 x3=x3(ones(1,N),ones(1,N),:);<span class="comment">%equivalent x3=repmat(x3,[N,N,1]);</span>
0017 
0018 X=x1.*x2.*x3;
0019 
0020 <span class="keyword">end</span>
0021</pre></div>
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